1. Field
The present invention relates generally to the field of communications, and more specifically, to communications in a cellular communication system.
2. Background
In code division multiple access (CDMA) communication systems, a number of users in the same geographical area may choose to operate on a common carrier frequency. The signal from each user is encoded according to a unique assigned code. A receiver may receive signals from different users with a common carrier frequency. While a signal for one user is being decoded, the signals transmitted from all other users may be treated as interference. A receiver decodes each signal according to the assigned code. Moreover, excessive transmission by a user may cause interference for other users in addition to causing system overload at a base station. In a CDMA system, the power level of the signals transmitted by different users of the system is controlled to control the interference level. The power level of each signal is controlled at the transmitter to maintain an adequate quality of reception at a receiving end. Other reasons, such as conserving battery power, for controlling power level of signals in a CDMA system are well known by one of ordinary skill in the relevant art.
Although the power level of the transmitted signal from each user is controlled to maximize the use of the available channels, there is a need for an increased mobility and higher quality of communication services. Such communication services may include wireless radio transmission of digitized speech, still or moving images, text messages and other types of data. The communication channel between a mobile station and a base station may be over two or more related communication channels. One of the channels may be a fundamental channel, and another may be a supplemental channel. The fundamental channel may serve as the primary channel for all the traffic communications between the transmitter and the receiver. The supplemental channel may carry additional data. The supplemental channel may be bursty. The gain level of each channel may be based on the received quality level at the receiver. However, the bursty nature of the supplemental channel may create an inefficient power control scheme in the communication system. The power level may be based on the gain level of each communication channel through a power control scheme in the communication system.
To this end as well as others, there is a need for an efficient gain control of the supplemental channel in a communication system.